One thing I discovered about lightweight springs is that lubing the switch doesn't work at all, it just stops resetting. I also think that with traditional MX-style switches going with weight less than 20g might not work out well because even with 20g springs some of my keys are not resetting properly, they remain stuck when I lift my finger, and I get "aaaaaaaaaaaaaaaa"s instead of just "a" for example.
As for removing keycaps, my keyboard looks like this: m.youtube.com/watch?v=647FeK3\_Bek, except I left the spacebar keycap on, and I have a small piece of adhesive plaster tape on top of the plastic parts that resembles a plus sign "+" on every switch to increase friction. But I don't think removing keycaps works for switches box type switches with stems that look like [+]. I also had to open the space bar switch and add a little aluminum foil ring inside where the spring is located because it consistently wouldn’t reset.
Lightweight springs also slightly reduce the key travel distance, and the actuation point becomes very high, practically no actuation point. It produces a keystroke the moment you touch it. This is now possible with harder springs too with the advent of Hall effect keyboards, but the lightest spring available for that type of keyboard is 28g, which is a bit too heavy.